1. Field of Invention
This invention relates to timing devices, specifically to alarm clocks.
2. Description of Prior Art
The need for help to awaken from sleep is so prevalent as to have spawned a vast variety of solutions over the centuries. When people share a room the problem becomes even more complex: sleepers often wish to wake without waking their roommates (to avoid the consequent wrath). If the sleeper happens to be particularly hard of hearing, he risks not awakening at all, or waking others in nearby rooms. We wish to reliably awaken one sleeper without disturbing others.
Existing solutions range from the nearly adequate to the silly. They include pillow vibrators, vibrating wrist bands, audio alarms placed in or under the user's pillow, and even alarms that sit in the user's ear. But, all existing solutions have significant limitations.
U.S. Pat. No. 5,072,429 to Mair (1991) tries to deal with the problem by placing the alarm sound closer to the sleeper, so that it doesn't have to be loud enough to wake anyone else. Specifically, Mair places the alarm within a special pillow. Another common solution is a small speaker placed under the pillow, attached to the earphone jack of a conventional clock-radio. But such arrangements are relatively useless for waking a heavy sleeper without waking light sleepers in the same room. Light sleepers are often far more sensitive to sounds, so that a small difference in proximity is not enough to shield them. Even without this limitation, a restless sleeper is likely to remain asleep after moving off their pillow or shoving the device aside. U.S. Pat. No. 2,517,368 to Wiseley (1950) carries this idea to the limit by using a hearing-aid speaker. But in both concepts there is a significant safety hazard. Both require wires in which the sleeper can become entangled during sleep.
Pager type watches, such as U.S. Pat. No. 5,297,118 to Sakumoto (1994), could be used for a similar function. But again, there is the problem of making it loud enough to reliably wake the sleeper without waking anyone else. Particularly if the sleeper's arm wanders under the covers, this is a serious limitation. Anything loud enough to wake the sleeper in this circumstance will certainly wake their roommates when the alarm is above the covers. Also, this approach is still dependent upon an external timing source.
U.S. Pat. No. 4,093,944 to Muncheryan (1978) and U.S. Pat. No. 5,144,600 to Cheng (1992) avoid the sound volume problem by placing vibrating devices under the sleeper's pillow. Of necessity, the devices are relative large and inconvenient. U.S. Pat. No. 4,920,525 to Meister (1990) expands this idea to a more general purpose timer and battery-powered vibrator, but with similar limitations. Vibrating devices that are not physically attached to the sleeper are relatively useless for the restless: they are too easily pushed aside during sleep.
U.S. Pat. No. 5,764,594 to Berman (1998) and U.S. Pat. No. 5,686,882 to Giani (1997) overcome this difficulty by using a vibrating wrist band. The vibration is triggered by a signal from a separate base station which actually does the timing. The operation of the wrist band is completely dependent upon the base station. It cannot be separate from it by more than a short distance (based on the signal range). A power failure in the base station prevents the alarm from operating, and lets the user over-sleep. This tightly-coupled configuration requires additional complexity in the base station to support additional independent wrist bands, hence Berman's stated intent to wake the second sleeper via the audio alarm. It also requires the wrist-band electronics to be active all the time, listening for an alarm signal, driving battery consumption.
The same basic problem plagues U.S. Pat. No. 5,894,455 to Sikes (1999). Here, the wristband is replaced with an ear-piece, and vibration with an audible alarm. Since the sound is emitted directly into the ear, it can easily be loud enough to wake the sleeper without waking anyone else. But, this approach has the same flaws as Berman's, in that it is totally reliant upon the base station. Also, the electronics must continually listen for an alarm signal, wasting battery power.
U.S. Pat. No. 4,456,387 to Igarashi (1984) avoids these problems by using an autonomous vibrating watch. However, those of us who have nearly jumped out of our skins when a vibrating pager “went off” would not consider this a pleasant way to awake. A rude awaking can degrade both attitude and productivity for the entire day.
U.S. Pat. No. 4,821,247 to Grooms (1989) bypasses virtually all of these problems with an in-ear alarm clock. But, this approach creates new problems. Since the device is entirely self-contained, it has buttons and a display for setting the time and alarm functions. This simultaneously makes the controls too small for convenient use, and makes the ear-piece far too large for comfortable wear during sleep. It is large enough to be quite uncomfortable, and to be easily brushed from the ear during sleep. Older users, in particular, would still have to find their reading glasses to set the alarm.